ATECO code: what it is, and why the choice changes the tax you pay

Italy's flat-rate regime taxes revenue through a profitability coefficient that runs from 40% to 86% depending on the ATECO code you file: at the same revenue, a different code means a different taxable base, and so a different tax bill. Yet the ATECO code is often picked in a hurry, when opening a VAT number, as if it were a form field to fill in without much thought. It isn't.

What the ATECO code is, and who reads it besides you

The ATECO code is the classification of economic activities adopted by ISTAT, Italy's national statistics institute: an alphanumeric string that describes, in a standard way, what your business does. It's not just the Revenue Agency that reads it: the same code reaches the Business Register, INPS and INAIL, each of which applies its own rules on top of it.

A new classification, ATECO 2025, derived from the European NACE Rev. 2.1 standard, has been in force since 1 January 2025, and operational for taxpayers and administrations since 1 April 2025. The Revenue Agency clarified this with Resolution no. 24/E of 8 April 2025: anyone filing returns or documents from that date uses the new codes, but the classification switch by itself doesn't require filing a data-change declaration. Your current code, old or already updated, shows up in your tax drawer (cassetto fiscale) on the Revenue Agency's site, under Consultazioni, Anagrafica.

Why the wrong code literally costs money

Anyone on the flat-rate regime doesn't calculate tax by subtracting actual costs from revenue, the way the ordinary regime works. Instead, a fixed profitability coefficient set by law, different sector by sector, is applied to revenue: that number, not real costs, becomes the base the tax is calculated on. The table, now in Annex 2 to Law 145/2018 (which replaced the original one in Law 190/2014, the law that created the flat-rate regime, with percentages unchanged since 2015), runs from 40% to 86% by ATECO group:

• 40%: wholesale and retail trade, food and beverage industries, accommodation and food service
• 67%: other economic activities not listed elsewhere
• 78%: professional, scientific, technical, healthcare, education, financial and insurance services
• 86%: construction and real estate activities

Two businesses with the same revenue, but ATECO codes from different groups, pay tax on a different taxable base, not by choice, but because the law treats sectors differently. A code chosen carelessly, maybe copied from an online list or suggested on the fly by whoever files the paperwork, can translate into taxation that doesn't reflect the actual business, on top of making the filed profile less consistent if it's ever checked.

How to fix it, and what it costs

The first step is checking the current code: the tax drawer for anyone with a VAT number, the company register extract for anyone also registered with the Business Register. If the code doesn't match the actual activity, how you fix it depends on how the VAT number was opened.

A sole professional not registered with the Business Register corrects the code with form AA9/12, even online through the Revenue Agency's own portal: no cost, no stamp duty. A business registered with the Business Register, such as a commercial or craft sole proprietorship, or a company, instead goes through the single business communication channel (Comunicazione Unica): here the cost is real, stamp duty plus secretarial fees, around 35 euros for a sole proprietorship, up to around 150 euros for a company, with amounts that vary slightly from one chamber of commerce to another.

Neither path is retroactive: the correction changes the coefficient applied from that point forward, not the one already used on returns already filed. Fixing an error on a closed tax year needs a different procedure, such as a voluntary correction (ravvedimento operoso), not a simple code change.

The right time to pay attention is before, not after

The ATECO code doesn't just feed the tax system: it also feeds the INAIL classification used to calculate workplace insurance premiums, and for anyone applying to public grants or calls, it's often the criterion the funding body uses to decide who can even apply. The same logic applies here as to other choices made when opening a business that you live with for years if you get them wrong, like the legal form, which I cover in sole proprietorship, SRLS or SRL: how to choose, or the name you take to market, covered in how to register a trademark. A few extra minutes reading the code's official description, not just its generic title, or one direct question to your accountant before signing the opening paperwork, cost less than a correction made afterward.

If you've just opened your VAT number and the next box to tick is getting found online, I cover that in website services. If you already have an active business and want to know where to start with your digital presence, get in touch: a couple of lines about your situation are enough.